As the war in Afghanistan begins to wind down, more and more troops are coming home. This year alone, more than 200,000 troops will be heading home into the civilian world, according to the Department of Veterans Affairs.

As they search for jobs and careers in this difficult economy, there is a growing movement among business people, experts and even celebrities to volunteer their time to be mentors for the troops.

Standing Up For Heroes is partnered with American Corporate Partners (ACP), a nonprofit organization dedicated to assisting veterans in their transition from the armed services to the civilian workforce, which is where Army Staff Sgt. Gabriel Posey applied to be part of a mentorship program.

When Posey, an aspiring screenwriter, stepped off the plane in Los Angeles, he knew he was matched up with a mentor in the entertainment business but he had no idea who it would be.

As part of ABC News' Standing Up for Heroes series, Posey was paired with Academy Award-winning actor Tom Hanks, who will mentor Posey in his pursuit of a career in the entertainment industry.

Posey, 32, was in the military for nine years. He was deployed to Guantanamo Bay, Cuba, and recently returned from the sands of Afghanistan. Now he hopes to pursue a career as a writer for either television or film.

Over a pot of tea, the sergeant got the chance to learn more from the actor-writer-producer.

"A writer writes a screenplay and everybody gets to tear it apart and go back at it and says change this and why is this here," Hanks told Posey. "The best writers that I know of, the best writers that I've worked with truly have no egos as far as the collaborative process."

Posey, of Melrose Park, Pa., said his plan is to get a job in the industry while he continues to write. Hanks agreed that he should always be writing, although that can be difficult at times.

"The screenwriters I know say it is a lonely horrible existence, that they spend far too much time sitting going through, cutting stuff that they have created and going back and starting all over from square one," Hanks said. "But you have chosen the one area for which there is no shortcut."

Hanks has been acting for more than 30 years, he has won two Academy Awards and been in more than 40 films, including huge hits such as "Forest Gump" and "Saving Private Ryan." He said the business is changing and the paychecks aren't as big as they once were. Industry executives are making fewer films and pushing for more original content.

But while the business is never easy, Hanks said, it's a lot more fun than many people on the inside let on.

"The secret that we all keep tucked in our pockets is that it's a great hang," Hanks said. "It is a great place to go every day and the demands that they place on you just really makes you. It's just more fun than fun can be. But we don't tell people that. We just talk about how hard the work is."

When Hanks was young, he traveled to New York City for the first time to pursue a career as a professional actor. But he was completely unaware what he was getting himself into.

"For some reason I was sent on an audition for a Maxwell House coffee commercial," Hanks said. "I didn't know where the building was, I didn't know what the office was, I eventually found it and a guy said, 'OK, stand over there and slate it' and I didn't even know what it meant. I stood over there and he said, 'Yeah, slate it.' And I said, 'What?' 'Slate it.' And I said, 'I don't know, I don't know what slate is.' 'Say your name.' And obviously I didn't get that thing. So you have to be willing to go through that."

As for Posey, he has plans to move to Hollywood to try to fulfill his lifelong dream and to stay in touch with his new mentor.

"It's a grand adventure, man," Hanks said. "So keep writing and keep reading; read everything, write everything, and see every movie that is out there."